Cilic fired 29 winners to advance to the last eight in the French capital for the third straight year.

The win improved the Croat's prospects of making the ATP Finals in London starting on November 11.

"I am very close to London, to securing my spot mathematically," said Cilic, who is part of the Croatia team facing France in the Davis Cup final at the end of this month.

"In the next match against Novak it will be another big challenge. (It will be) great to play him again."

Cilic, who will guarantee making the cut for London if he downs Djokovic, was ending reigning ATP Finals champion Dimitrov's season.

Dimitrov has been coached by a former coach of Djokovic, eight-time major winner Andre Agassi, in Paris this week.

Djokovic and Cilic were later joined in the quarter-finals by Karen Khachanov who saved two match points agaisnt John Isner on his way to defeating the eight-seeded American 6-4, 6-7 (9-11), 7-6 (10-8).

The Russian will next play Alexander Zverev after the German fourth seed beat Diego Schwartzman of Argentina 6-4, 6-2.